Only the error bars for the selected data series are modified. To change error bars for another series, click one of its error bars, then make changes.
When you create a chart, Auto-Fit is automatically turned on for error bars to prevent overlap. To see all error bars, deselect the tickbox next to Auto-Fit.
To remove error bars, click the chart, click an error bar, then click the Error Bars pop-up menu in the sidebar and choose None.
Trendlines show you the overall direction (or trend) of your data. Trendlines appear in bar, line, scatter, bubble, column and area charts.
To remove trendlines, click the chart, click a trendline, then click the Trendlines pop-up menu in the sidebar and choose None.